Prep Your Baking Tools
Line baking sheets with parchment paper and preheat your oven to 350°F (177°C).

Make the Dough
In a large bowl, cream the softened butter, sugar, and vanilla until light and fluffy. Add the salt and gradually mix in the flour until a soft dough forms.

Prepare the Filling
In a separate bowl, mix together the brown sugar, cinnamon, and softened butter until fully combined and smooth.

Assemble the Cookies
Take a small piece of cookie dough and roll it into a ball. Set it on the lined baking sheet and lightly press it down using your fingertips or the base of a glass. Add a spoonful of the cinnamon-sugar mixture to the center.

Seal the Cookie
Place another small dough ball on top and press the edges together to fully enclose the filling, forming a little stuffed cookie.

Bake
Bake for 8–10 minutes or until the edges are set and just lightly golden. Take them out of the oven and allow them to cool fully right on the baking sheet.

Make the Glaze
In a bowl, combine milk, powdered sugar, and a dash of cinnamon. Mix until smooth. Adjust the thickness by adding more powdered sugar or milk as needed.

Glaze and Garnish
Once cookies are completely cool, drizzle a spoonful of glaze over each and sprinkle with a touch of cinnamon.